code: def test_prophet_model_default_with_prophet_constructor(self):
      from prophet import Prophet as FBProphet
  
      model = Prophet()
      assert (
          model._model_builder == FBProphet
      ), "model should use Facebook Prophet"
  
file_path: darts/darts/tests/models/forecasting/test_prophet.py
imports: from unittest.mock import Mock
  import numpy
  import pandas
  import pytest
  from darts import TimeSeries
  from darts.logging import get_logger
  from darts.models import NotImportedModule, Prophet
  from darts.utils import timeseries_generation
label_desc: Use image node_id 5 for calling the TestProphet obj's underlying member method code with example usage: obj.test_prophet_model_default_with_prophet_constructor() without return types